Three-dimensionalization of semiconductor devices may cause an increase in the surface area of the structures formed above the semiconductor substrate during the manufacturing process flow. When forming a film by CVD (Chemical Vapor Deposition) for example, the supply of reaction gas increases as the surface area of the underlying structure becomes greater. Thus, formation of a film above a semiconductor substrate having a large surface area requires a large amount of reaction gas, which in turn increases the cost of semiconductor device manufacturing.